As real-world tasks grow increasingly complex, long-context reasoning has become a core capability for Large Language Models (LLMs). However, few studies explore which data types are effective for long-context reasoning and why. We find that structured table data with periodic structures shows strong potential for long-context reasoning. Motivated by this observation, we mathematically analyze tabular dependency structures using mutual information, revealing periodic non-vanishing dependencies in table data. Furthermore, we systematically analyze the capabilities of structured table data, conduct relevant scaling experiments, and validate its underlying mechanisms for enhancing long-context reasoning, yielding several meaningful insights. Leveraging these insights, we propose a simple yet scalable pipeline(TableLong) for synthesizing high-quality, diverse, and verifiable structured table data to boost long-context reasoning via RL. Extensive experimental results demonstrate that table data significantly enhances the long-context reasoning capability of LLMs across multiple long-context benchmarks (+8.24% on average), and even improves performance on out-of-domain benchmarks (+8.06% on average). We hope that our insights provide practical guidance for effective post-training data to enhance long-context reasoning in LLMs.
Figures & tables
Figure 1: Overview of TableLong: An end-to-end table data construction pipeline for long-context reasoning.
Figure 2: The radar chart of long-context reasoning benchmarks for DS-R1-Distill-32B trained with varying length.
Model
LB-v2
Loong
Brows
GSM-Inf
Oolong
Ruler
MRCR
Avg.
Reference Flagships & Baselines
Gemini-3.0-pro
69.38
65.43
88.07
87.06
78.41
83.01
75.30
78.09
Deepeek-v3.1
52.88
50.55
56.27
47.40
51.90
42.97
46.62
49.80
Qwen-Long-L1
43.74
44.68
69.93
9.00
27.37
47.70
27.70
38.59
Main Results: Effectiveness of Our Method
Qwen3-32B
46.33
39.96
59.33
12.22
31.66
50.86
42.45
40.40
Table 1: Performance Comparison on Long-Context and Reasoning Benchmarks. We compare base models against their variants optimized via Reinforcement Learning on our dataset (denoted as + Ours ). The best results within each model family are highlighted in bold . LB-v2 : LongBench v2; Brows : BrowsCompLong; GSM-Inf : GSM-Infinite; Oolong : Oolong-Synth. For model names, Qwen2.5-32B-Inst denotes Qwen2.5-32B-Instruct, and DS-R1-Distill refers to Deepseek-R1-Distill-Qwen.
Figure 3: Needle in a Haystack retrieval across document depths. Our approach significantly enhances long-context robustness, boosting the 14B model’s accuracy from 69.30% to 91.20% and the 32B model’s accuracy from 87.95% to 99.40%, achieving near-perfect performance.
Figure 4: Decomposition experiments for DS-R1-Distill-32B. (a) While structure alone (“no semantics”) boosts baseline performance (+1.67%), semantics remain essential for peak results. Removing delimiters or adding noise yields negligible drops, confirming the primacy of intrinsic structure. (b) Models with “no semantics” suffer premature convergence, whereas “no visible delimiters” settings recover from low initial rewards.
Model
LB-v2
Loong
Brows
GSM-Inf
Oolong
Ruler
MRCR
Avg.
DS-R1-Distill-32B
∣− 0 ∼ 30
44.33
42.87
71.87
18.00
40.29
69.30
37.44
46.30
∣− 0 ∼ 100
45.33
43.46
74.31
10.00
44.10
71.82
36.46
46.50
∣− 0 ∼ 300+
45.73
45.30
74.31
14.80
51.41
66.41
40.57
48.36
DS-R1-Distill-14B
∣− 0 ∼ 30
36.98
35.60
72.17
6.40
41.70
82.16
27.63
43.23
Table 2: Performance comparison across varying scales of table cells. Bold values indicate the best performance within each backbone.
Model
LB-v2
Loong
Brows
GSM-Inf
Oolong
Ruler
MRCR
Avg.
DS-R1-Distill-32B
∣− 1
44.93
43.65
73.39
16.80
50.78
62.97
34.10
46.66
∣− 1 ∼ 5
45.33
44.27
73.37
15.00
49.63
64.37
37.79
47.11
∣− 1 ∼ 30
45.73
45.30
74.31
14.80
51.41
66.41
40.57
48.36
DS-R1-Distill-14B
∣− 1
34.39
37.05
71.25
6.20
42.09
77.03
31.59
42.80
Table 3: Performance comparison across varying scales of table count. Bold values indicate the best performance within each backbone.
Model
GPQA
AIME
MC
LCB
DS-R1-Distill-32B
56.06
60.00
30.28
46.71
DS-R1-Distill-32B + Ours
63.64
70.00
32.97
58.68
DS-R1-Distill-14B
55.56
43.33
23.08
43.71
DS-R1-Distill-14B + Ours
59.60
46.67
26.86
45.51
Table 4: Generalization on OOD Benchmarks. We evaluate models on GPQA-Diamond ( GPQA ), AIME 2025 ( AIME ), MultiChallenge ( MC ), and LiveCodeBench ( LCB ). Shaded rows indicate our RL-finetuned models ( + Ours ). Our method achieves significant gains, notably +11.9% on LCB for the 32B model.
Appendix figures & tables19 assets
Supplementary material from the paper’s appendix.
Appendix
Hyperparameter
Value
Computational Setup
Hardware
64 × NVIDIA H20
Parallelism Strategy
TP=8
Offload
Disabled
Training Parameters
Max Sequence Capacity
32,768
Appendix
Table 5: Detailed hyperparameters for RL training
Category
Benchmark
Subset / Task
Num. Samples
Domain Focus
Holistic
LongBench-v2 ( Bai et al., 2025 )
Full Set
503
General Real-world
Loong ( Wang et al., 2024 )
Full Set
1,441
Spotlight QA / Retrieval
Retrieval
Browscomplong ( OpenAI, 2025a )
Standard
327
Complex Search
MRCR ( OpenAI, 2025c )
Standard
1,437
Multi-round QA
Ruler ( Hsieh et al., 2024 )
QA2 Task
2,495
Variable Tracking
Reasoning
GSM-Infinite ( Zhou et al., 2025 )
Standard
500
Long-range Math
Appendix
Table 6: Details of the evaluation benchmarks for long-context reasoning. ”Subset/Task” indicates the specific evaluation partition used. ”Num. Samples” denotes the number of test instances after filtering.
Category
Benchmark
Num. Samples
Domain Focus
Science
GPQA-Diamond ( Rein et al., 2024 )
198
Scientific Reasoning
Math
AIME 2025 ( Balunović et al., 2025 )
30
Mathematical Reasoning
Multi-turn Dialogue
MultiChallenge ( Deshpande et al., 2025 )
273
Real-world Multi-turn Dialogue
Code
LiveCodeBench ( Jain et al., 2024 )
167
Code Generation
Appendix
Table 7: Details of the evaluation benchmarks for other domains. ”Num. Samples” denotes the number of test instances after filtering.
Figure 5: Decomposition experiments for DS-R1-Distill-14B. (a) While structure alone (“no semantics”) boosts baseline performance (+1.66%), semantics remain essential for peak results. Removing delimiters or adding noise yields negligible drops, confirming the primacy of intrinsic structure. (b) Models with “no semantics” suffer premature convergence, whereas “no visible delimiters” settings recover from low initial rewards.
Model
LB-v2
Loong
Brows
GSM-Inf
Oolong
Ruler
MRCR
Avg.
DS-R1-Distill-32B
∣− 4k
45.13
43.41
74.92
11.60
47.65
68.42
37.65
46.97
∣− 8k
48.11
43.89
74.01
13.20
47.87
66.05
39.04
47.45
∣− 16k
45.73
45.30
74.31
14.80
51.41
66.41
40.57
48.36
DS-R1-Distill-14B
∣− 4k
36.78
36.03
74.31
8.00
43.81
80.08
30.27
44.18
Appendix
Table 8: Performance comparison across varying scales of length. Bold values indicate the best performance within each backbone.
Figure 6: Performance comparison on the 16k+ length range of LongBench-v2.
Model
0-4k
4k-8k
8k-16k
16k-32k
32k-64k
64-128k
DS-R1-Distill-32B
63.82
51.50
38.50
28.75
23.00
26.25
DS-R1-Distill-32B + Ours
69.49
62.75
55.50
45.25
38.50
39.00
DS-R1-Distill-14B
62.31
51.00
45.50
37.25
31.25
27.00
DS-R1-Distill-14B + Ours
66.30
52.50
47.75
40.00
33.50
34.75
Qwen3-32B
60.66
40.25
33.25
20.50
11.75
15.00
Qwen3-32B + Ours
63.69
53.75
53.00
35.75
28.25
24.25
Appendix
Table 9: Oolong-Synth performance across different length ranges
Model
0-4k
4k-8k
8k-16k
16k-32k
32k-64k
64k-128k
DS-R1-Distill-32B
-
39.43
38.52
30.41
27.46
25.62
DS-R1-Distill-32B + Ours
-
50.81
47.04
40.54
36.61
30.31
DS-R1-Distill-14B
-
37.80
38.15
32.79
26.51
14.37
DS-R1-Distill-14B + Ours
-
44.31
34.07
28.04
25.76
22.81
Qwen3-32B
-
52.44
48.15
40.88
36.27
35.94
Qwen3-32B + Ours
-
52.44
45.93
42.23
41.36
33.44
Appendix
Table 10: MRCR performance across different length ranges
Model
0-4k
4k-8k
8k-16k
16k-32k
32k-64k
64-128k
DS-R1-Distill-32B
63.82
51.50
38.50
28.75
23.00
26.25
∣− 4k
70.70
61.50
52.75
39.50
31.25
31.75
∣− 8k
70.01
61.50
57.25
45.75
32.00
28.25
∣− 0-30
68.64
56.75
34.75
29.75
21.50
23.00
∣− 0-100
72.94
60.75
47.50
32.00
25.50
25.50
∣− 1
71.39
64.75
56.50
42.75
34.00
33.50
Appendix
Table 11: Oolong performance comparison across context lengths.
Group
Model
0-4k
4k-8k
8k-16k
16k-32k
32k-64k
64-128k
DS-R1-Distill-32B
-
39.43
38.52
30.41
27.46
25.62
Length
∣− 4k
-
48.37
44.81
33.45
34.92
29.69
∣− 8k
-
51.63
43.33
37.84
34.24
31.87
Cells
∣− 0-30
-
48.78
42.95
36.15
33.90
27.50
∣− 0-100
-
47.97
42.95
36.94
29.15
28.44
Tables
∣− 1
-
43.50
39.26
34.80
36.61
24.06
Appendix
Table 12: MRCR performance comparison across context lengths with grouping.
Figure 7: The instruction prompt used for generating SQL-NLQ pairs, which constrains SQL logic while eliciting natural, task-oriented questions.
Figure 8: An instance of the precise retrieval grounding task.
Figure 9: An instance of the multi-hop reasoning task.
Figure 10: An instance of the multi-table grounding task.
Figure 11: An instance of the semantic-agnostic table task.
Figure 12: An instance of the no-visible-delimiter task.
Figure 13: An instance of the no-visible-delimiter task with highlighted noise.
Figure 14: Comparison of reasoning chains. The baseline model (left) hallucinates column values (e.g., confusing ‘dst_ap‘ with ‘src_ap‘’s neighbor), while our model (right) correctly parses the row as a sequence.
Figure 15: Comparison of reasoning strategies on the AIME 2025 grid coloring problem. The baseline (DS-R1-Distill-32B) relies on exhaustive enumeration but fails due to symmetry bias (Result: 84). In contrast, our model employs algebraic modeling and variable reduction to enforce precise constraint propagation (Result: 82).